A refrigerant compressor includes a magnetic bearing assembly including insulation for the coils and lamination stack of the assembly. The lamination stack includes coil apertures extending axially between opposed axial faces. An insert partially extends into a first coil aperture to prevent direct contact between first and second coils. The insert includes a first leg extending into a slot formed in the lamination stack and a second leg radially spaced-apart from the first leg with the second leg extending axially into the first coil aperture. An annular cover having first and second legs extends into respective slots and apertures of the lamination stack. A second annular cover is provided on the opposite face of the coils that is connected to free ends of the second legs. The lamination stack and coils are coated with an insulative material such as epoxy.

There is provided a controller for magnetic levitation equipment comprising a plurality of current source modules for connecting to at least one power supply for direct current, DC, and said current source modules comprising current channels for actuating coils of the magnetic levitation equipment, and a controller device connected to the current source modules by a control connection for controlling switching of electric current by the current source modules to the current channels. The current source modules combine discrete components for amplifying and switching electric current to the current channels into a single package. In this way, manufacturing and maintenance of the controller is facilitated, since manufacturing and maintenance may be based on the current source modules instead of discrete components, e.g. gate drivers, IGBTs, power mosfets and diodes.

A weight compensating device includes a stator and a translator. The translator is movable relative to the stator along a movement axis. The translator includes a first permanent magnet arrangement with an axial magnetization. The stator includes a second permanent magnet arrangement radially surrounding the first permanent magnet arrangement. The stator includes a third permanent magnet arrangement that is coaxially below the first permanent magnet arrangement and that has an axial magnetization aligned in inverse fashion with respect to the axial magnetization of the first permanent magnet arrangement. The stator includes a magnetic body arrangement that is coaxially above the first permanent magnet arrangement. The first permanent magnet arrangement, the second permanent magnet arrangement, the third permanent magnet arrangement and the magnetic body arrangement form a magnetic unit and, in interaction with one another, form a compensating force that counteracts the weight acting on the translator.

Provided are a vacuum pump, a magnetic bearing device, and a rotor that suppress swinging and vibration of a rotor. A vacuum pump includes, in the following order in the exhaust direction of a gas, the center of gravity of a rotor, an active radial bearing that supports the rotor in the radial direction in a non-contact manner by using a magnetic force, and a passive radial bearing that supports the rotor in the radial direction in a non-contact manner using a magnetic force.

A magnetic suspension bearing device, a compressor and a method for adjusting catcher bearing gap. The magnetic suspension bearing device includes: a housing; a rotor in the housing; a magnetic bearing assembly between the housing and the rotor; a catcher bearing bracket mounted axially to an end of the housing, with a catcher bearing mounted at a radially inner side of the catcher bearing bracket; and a washer between the catcher bearing bracket and the end of the housing; wherein the washer includes a plurality of sub-washer portions, such that when the catcher bearing bracket is moved axially relative to the end of the housing to separate from the washer while still being supported by the end of the housing, the plurality of sub-washer portions can be radially removed and mounted.

System for controlling at least one active magnetic bearing equipping a rotating machine comprising a rotor and a stator, at least one means for measuring the radial positions of the rotor as a function of the signal from at least one position sensor, and at least two control loops of the active magnetic bearing as a function of the radial positions of the rotor, each control loop of the magnetic bearing being provided with at least one synchronous filter as a function of the rotation speed, and an extended Kalman filter for determining the rotation speed of the rotor with respect to the stator receiving as input, from position sensors, measurements of radial position of the rotor and as a function of measurements of radial position of the rotor performed over a predetermined time at zero rotor rotation speed.

A magnetic levitation device as a toy or a bearing is provided. The magnetic levitation device has an inner component and an outer component. Multiple magnet rings are mounted on the inner component and multiple magnet rings are mounted on the outer component. The magnet rings on the inner component attract the magnet rings on the outer component. Multiple pulley assemblies are mounted on the outer component. An elastic component is connected with a center pulley. The two ropes are wrapped on the center pulley. One end of each one of the ropes is mounted on one of the fixing points that is connected to one of the magnet rings mounted on the outer component and another one end of the rope is mounted on a reactive pulley. With such structure, the outer component may levitate from the inner component and the pulley assemblies can balance the entire device.

A magnetic suspension bearing, a magnetic suspension bearing control system and a control method, the magnetic suspension bearing control system includes a processor, a synchronous signal generation module, a displacement signal conversion circuit, a post-processing circuit, an Analog-to-Digital conversion module, a pulse width modulation module, a frequency division circuit, a synchronization module, and a power amplifier. The magnetic suspension bearing includes the magnetic suspension bearing control system, a first iron core, a second iron core, a first and a second magnetic suspension bearing actuator coils wound on the first and the second iron cores respectively, and an electromagnetic force suspension rotor; wherein the first and the second magnetic suspension bearing actuator coils are oppositely disposed on upper and lower sides of the electromagnetic force suspension rotor, and both the first and the second magnetic suspension bearing actuator coils are connected with the magnetic suspension bearing control system.

This disclosure describes a system for sending control signals and receiving sensor signals over cables at long distances. Electric currents and signals traveling down long cables can undergo phenomenon that are not present in relatively short cables. Therefore, this disclosure contemplates solutions for overcoming or compensating for these phenomenon to enable control of an electric machine using long cables. The solutions can include a signal conditioning circuit, configured to output a DC current corresponding to the sensed voltage associated with the sensor, a first conductor, that transmits the DC current from the signal conditioning circuit to the controller, and a signal generator, configured to receive the command signals and generate pulse width modulated (PWM) actuating signals based on the command signals.

This disclosure relates to an axial magnetic bearing for a centrifugal refrigerant compressor, and a corresponding system and method. A centrifugal refrigerant compressor system according to an exemplary aspect of the present disclosure includes, among other things, an impeller connected to a shaft, and a magnetic bearing system supporting the shaft. The magnetic bearing system includes an axial magnetic bearing, which itself includes a first permanent magnet configured to generate a first bias flux, a second permanent magnet axially spaced-apart from the first permanent magnet and configured to generate a second bias flux, and an electromagnet. The electromagnet includes a coil arranged radially outward of the first and second permanent magnets, and the electromagnet is configured to selectively generate either a first control flux or a second control flux to apply a force to the shaft in a first axial direction or second axial direction opposite the first axial direction, respectively.